1. Field of the Invention
The invention relates to optical wavelength converters and methods and optical communication systems that use optical wavelength converters.
2. Discussion of the Related Art
Wavelength-division multiplexed (WDM) optical communication systems may advantageously incorporate optically pumped nonlinear optical devices such as optical wavelength converters and/or optical phase conjugators. As a first example, a WDM optical fiber line may incorporate an optical wavelength converter between adjacent optical fiber spans to enable the transfer of optical communications to different wavelength-channels in the adjacent fiber spans. The ability to change the wavelength-channel between adjacent fiber spans enables a more efficient use of the bandwidth in each fiber span of the WDM optical communication system. As a second example, a long-haul WDM optical fiber line may incorporate an optical phase conjugator. A suitably positioned optical phase conjugator can partially undo the pulse degradation due to nonlinear optical effects when optical pulses travel along a long optical transmission line. While such optically pumped nonlinear optical devices may have characteristics that make their incorporation into WDM optical fiber lines desirable, improvements to these nonlinear optical devices may be useful.